To put it bluntly: there is today only one way for large scale energy storage and that is pumped hydro. Look at the plot 2.5 minutes into the TEDx video of Don Sadoway.

The installed capacity of all other methods combined do not reach 1% of the installed capacity of stored hydro. Not for lack of trying, though. To prove this point (we try!) the trade fair “ENERGY STORAGE EUROPE 2018” was held in Düsseldorf from 13-15 March. Market-ready flywheel, redox flow and Power-2-X were passing the review at the conferences that accompanied the fair. (‘Market ready’ is a euphemism for: ‘Let us see if we can find the money to cross the valley of death.’)

Interest in the subject is illustrated by the fact that there were about 4.500 visitors from 61 countries and 170 exhibitors. Next year’s event will be held on 12-14 March 2019